Leakage in pipelines is a fairly wide spread problem and, in Canada and other countries with a harsh winter climate, the problem is one of increased frequency during the winter months due to the results of deep frost penetration. Moreover, older pipelines are very susceptible to leakage and fracture due to a variety of reasons in addition to movement in the lines caused by frost. It is often necessary to carry out pipeline repairs on short notice depending on the fluid or gas carried by the pipeline as environmental damages and other serious problems can result from a fracture and leak.
Conventional repair procedures can be a very expensive and time consuming in their applicability to a pipeline where a leak has occurred. There are several conventional approaches to the problem and while most of these approaches include a clamp that consists of a pair of complementary members in the form of two half-shells or half-sleeves, bolted together over the area of the leak, there are substantial differences with respect to the material used intermediate the half-shells and the surface of the pipe in the vicinity of the leak. In many cases, an annular web of material is wrapped around the area of the leak before the half-shells are applied thereover and secured together.
Another common approach is to incorporate the half-shells of a type that are capable of carrying a fluid under pressure and then injecting a high pressure sealing medium into the annular space between the interior of the half-shells and the exterior of the pipe, the pressure of the sealing medium being greater than that in the pipe.
Yet another approach utilizes a pair of mating coupler or clamping members that operate with a semi-circular liner that is inserted into the coupler members before they are clamped together to effect the seal.
Many of the conventional approaches, some of which are mentioned above, result in an expensive solution to the problem at hand due to the number of physical elements involved in the approaches and the time required in the procedures of applying those solutions. Some examples of these conventional approaches may be found in U.S. Pat. No. 4,819,974, Zeidler, Apr. 11, 1989; U.S. Pat. No. 4,768,813, Timmons, Sep. 6, 1988; and Canadian Patent 1,024,913, The Pipe Line Development Company, of Jan. 24, 1978.